1. Field of the Invention
The invention relates to an apparatus with adjustable freedom from backlash for a control device.
2. Description of the Background Art
Known from DE 102 20 889 B3, which corresponds to U.S. Pat. No. 7,171,887 is an adjusting device for hydrostatic piston machines. The adjusting device comprises an actuating piston which can be moved between two end positions and which can be subjected to actuating pressures acting on it in opposite directions. The actuating pressures can be regulated by an actuating pressure regulating valve serving as a control device. To this end, the actuating pressure regulating valve has a deflectable regulating piston to which is applied a regulating force that is a function of the position of the actuating piston. The regulating force is directed opposite to a control force acting on the regulating piston, and is zero in a rest position of the adjusting device. In the rest position of the adjusting device, the regulating piston is in its neutral position, and the actuating piston is in a position determined by the control of the valve. To produce the regulating force, an actuating lever, which is rotatably mounted on a bearing pin, is located in the actuating pressure regulating valve. The regulating force is a function of the angular position of the actuating lever. Also rotatably mounted on the bearing pin are a first arm and a second arm. The first and second arms are connected to one another by a tension spring, so that excursion of one of the two arms relative to the other arm causes stretching of the tension spring. A carrier pin is located at one end of the actuating lever. During a rotation of the actuating lever about the bearing pin, the carrier pin rests against one of the arms. Under tension of the spring, the other arm bears against a support provided on the regulating piston, thus applying the regulating force to the support.